Wound Healing Without Scars?

Scar formation happens in adult mammals because skin regeneration does not fully occur. In a newly published article, a team of researchers investigated the use of the adult newt, Cynops pyrrhogaster, as a model system for studying scarless wound healing for technology development in surgical and cosmetic medicine.

After an injury occurs, the epidermis can grow and migrate to fill in the wound. This is known as re-epithelialization. Although this takes place, the original skin color and texture is sometimes not retained, leading to the appearance of what we know as a scar. Processes called granulation and dermal fibrosis underpin scar formation, making them a focus for scientists aiming to minimize scarring following clinical procedures. Amphibians have been used as animal models for studying this, because they do not scar prior to metamorphosis. 

“We chose to examine the adult Japanese fire-bellied newt” explains Dr. Tatsuyuki Ishii, lead author of the study. “We know adult newts are capable of complicated tissue, organ, and limb regeneration. Despite that, their ability to regenerate skin has not been scientifically demonstrated.”

The team excised a small piece of skin from various body parts of adult newts. They periodically observed the skin healing and regeneration progression for up to two years, making note of re-epithelialization and dermal fibrosis, as well as recovery of texture, appendage, and color.

“Interestingly, we found that the adult newts could successfully and fully regenerate their skin at each part of the body that we examined,” describes Professor Chikafumi Chiba, senior author. “Re-epithelialization occurred at all locations, while no dermal fibrosis was observed at all.”

Overall, these findings will be crucial for future studies in humans focusing on efforts to prevent scarring in human skin following various medical procedures.


Tatsuyuki Ishii, Ikkei Takashimizu, Martin Miguel Casco-Robles, Yuji Taya, Shunsuke Yuzuriha, Fubito Toyama, Fumiaki Maruo, Kazuo Kishi, Chikafumi Chiba. Skin Wound Healing of the Adult Newt, Cynops pyrrhogaster: A Unique Re-Epithelialization and Scarless Model. Biomedicines, 2021; 9 (12): 1892 DOI: 10.3390/biomedicines9121892

University of Tsukuba. “Can we go from scarface to scarless?.” ScienceDaily. ScienceDaily, 5 January 2022. <www.sciencedaily.com/releases/2022/01/220105111430.htm>.

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Photo by Precious Irogalachi